Shock-absorbing device for appliances, such particularly as aircraft parachutes



TRICAU SHQCK ABsoRBING DEvcE FOR APPLIANCES, SUCH 5 Sheets-Sheet l -Nov. 14, 1933. G.

PARTICULARLY As AIRCRAFT PARACHUTES Filed May '21, 1932 l l l maximums:

Nov. 14, 1933. G 'rRlcAu 1,935,339v

.sHocK ABsoRBING DEVIQEy FoR APPLIANCES, sucH PARTICULARLY As AIRCRAFT PARAcHUTEs Filed May 2l, 1932 5 Sheets-Sheet 2 Nov. 14, 1933. G, TRlCAU 1,935,339

SHOCK ABSORBING DEVICE FOR APPLIANCES, SUCH PARTICULARLY AS AIRCRAFT PARACHUTES Filed May 21, 1932 5 Sheets-Sheet 3 gw@ GLW Nqv 14, 1933.

Y G. TRICAU SHOCK ABSORBING DEVICE FOR APPLIANCES, SUCH PARTICULARLY AS AIRCRAFT PARACHUTES Filed May 2l, 1932 5 Sheets-Sheet l1:

NOV- 14,1933-, G. TRlcAU 1,935,339

SHOCK ABSORBING DEVICE FOR APPLIANCES, SUCH PARTICULARLY AS AIRCRAFT PARACHUTES Filed May 21, 1952 5 sheets-sheet 5 patented Nov. i4, iets ,935,339

ITED SHCK-SORBNG DEVICE FR APPLI- ANGES, SUCH PARTI@ AS AIB.- CRAF'E PARACHEJTES Gabriel '.lricau, Vanves, France Application May 2li., 1932, Serial No. 612,685, and in Luxemburg May 28, 1931 8 Claims. (Cl. 24d-2l() This invention relates to shock absorbing deripping of the shock absorbing strap to avoid the vices used in appliances, such as aircraft paracomplete rupture thereof, and chutes, forabsorbing the shock to which the load Figs. 12 and 13 are perspective and plan views, being transported by an appliance is subjected, respectively, f 2 shock nbselbng devise embodyas for example, when the sail of a parachute ing the invention showing a modied form of 60 opens. rupture elements thereof having weft threads The said load after being thrown in space with and comprising a suitably formed strap. the parachute to Which'it is attached, results in Accordingly. the invention provides e sneek eba free fall and acquires a certain speed. Upon sorbing device adapted t0 be intepesed between d opening of the sail of said parachute, its fall 'is the leed suspension means 0f the Seil and the 65 so suddenly braked or retarded that it receives nd itself in the following manner:

a very violent shock. The degree of seventy or There is provided a strap a, nve centimeters the shock is directly proportional to the durawide, for exemple having tw@ 100138 b formed tion of the period oi vfree fall and the mass of @ne ai? eeen endld'tbe load. 'The strap a is folded back on itself and rows 70 The invention has for its object the provision 0f Stitches c of silk twist or the Vlike are made of shock absorbing devices of the above men- With e Sewing machine inthe direction of the tioned type, which are constructed to efficiently weft. y absorb the shocks arising from the very rapid These IGWS of Stitches c may be spaced aperti 2d braking caused by the opening of the sails of two millimeters and several hundred oi them are 75 said appliances. Previded In the accompanying drawings: v One of the loops b of the strap a is tied to Figs. l, 2, 3 and 4 are views, shown partly diathe shroud lines d and the belt e of the paragrammatic, of a shock absorbing device part comehuiist is passed through the Other 0f Seid 100125- prising a strap constructed to embody the inven- This shock absorbing device thus constituted 30 tion. rlhese figures illustrate, respectively, the and interposed between the shroud lines and progressive steps taken in the manufacture of the belt of the paraehuiisi, Operates es fOllOWS:

said strap. When the parachute opens in use, a shock is Fig. 5 is a fragmentary perspective view, shown transmitted to the strap between the loops there- 3d partly diagrammatic, of a complementary shock 0f and causes the rows of stitches to be ruptured 35 absorbing means positioned on the shroud lines in succession. Each row of stitches on being of a parachute embodying the invention. ruptured, absorbs a portion of the shock and Fig. 6 is a fragmentary sectional View, shown if .the resistance oi each stitch to rupture and partly diagrammatic, of the resilient ring sethe number of rows of stitches are suicient, the

cured to the pa; .shute shroud lines. user will flnally'hang from the shroud lines of gg Fig. 7 is afragmentary perspective view, shown the parachute Without being subjected t0 any partly diagrammatic, of the shock absorbing deappl'eeiefble sneekvice and complementary means applied to the Thus, by using an ample number 0f rOWS 0f Shroud unes of a parachute stitches to assure sumcient resistance, the shock 40 Fig. Sis a fragmentary perspective view, shown can be reddily reducd t0 any desired degree and 95 partly diagrammatic, of a. shock absorbing device .can practlcauy b? ehmma'tedin an initial position, the rupture elements of As shown m ,Flgs' 5 6 and 7 the mid'pofblon said device being constituted of weft threads comgf the Shtoud lmes d of th? Parachute are held psng a suitably formed Strap ogether in a gathered position by means of a F, 9 f t t. .m resilient ring f, the latter embracing the shroud 100 1g' .1S a' ragmgn ary persfpec We Vlew lines d and bending them. Said resilient ring ilar to Fig. 8, showing the device after opera ion f is held in the position shown in Figs. 5 and 7 v and'ripplngl of a portion of the rupture elements. by means of Smau loops g as Shown in detail Fig. 10 1s a fragmentary perspective View, in Fig. 6, Said loops g being made of braid and 5o shown partly diagrammatic and Similar t0 FisS- sewed to the shroud lines d. The ring f is sub- 105 8 and 9. after Operation end'eemplete ripping 0f jected to a tension stress by the action of the the rupture elements. shroud lines in receiving a shock and thereupon Fig. llisairagmentary perspective view, shown exerts a pull on the shroud lines and compels partly diagrammatic and similar to Figs. 8,. 9 and each to support a part gf the shock. Aaid ring 455 1G, but including a safety cable for limiting the thereby relays the effect "of the successive shcck 110 on the rupturing elements. The action of the resilient ring f causes:

(a) The shock determining the ripping of the first element to be ruptured to resemble a shock exerted on two perfectly resilient bodies;

(b) The distribution of the load on all the shroud lines;

(c) The successive effects on the rupture elements to resemble the eiect of a continuous force.

In order to provide a shock absorbing device of the character described above, but adapted to insure a more rapid yet a very gradual braking action, the modified form of the invention may be adapted by using a strong strap h, ten centimeters wide for example, made of woven hemp, flax, silk or other suitable material.

In one end of this strap, a slot about thirty centimeters long for example, is formed in the direction of the warp and at the middle portion of the strap, that is to say, by cutting the weft threads. At the other end of the strap, a similar slot is formed, but longer, for example fortyv centimeters long.

As shown in Fig.8, the strap h is folded back on its self, by placing both ends one rover the other. A loop is formed with the two left-hand halves z' of the strap, by folding them and by firmly sewing together the four strap thickness thus obtained. A loop Z, similar to loop i above described, is formed with the two right-hand halves 1c of the strap, and, at the middle and all around the folded strap, a strop m, having for instance three turns, is formed by means of a rope made of silk or of any other material of suitable strength.

The shock absorbing device thus devised is attached to the parachute and user as shown in Figs. 8 to 11, inclusive, in the following manner:

'Ihe belt n of the parachutist is passed through one of the loops of the strap h, for instance the loop l, and the free end of the shroud lines d of the sail is attached to the other loop y'.

Being thus attached to the parachute, the said device operates as follows:

After the parachutist has jumped overboard, or after the fall of the load, when the sail opens, the shroud lines d of the sail are stretched. rThe strap ih, secured, on the one hand, to the belt n of the parachutist, is torn, thus absorbing the shock produced by the opening of the sail, first slightly, then more effectively when the rent caused to the rst or shorter slot-makes the latter equal l to the second or longer slot.

If the shock is sulllciently powerful for completely tearing the strap, the latter is divided into two parts which are connected end to end by the strop m and will sustain the user as shown in Fig. 10.

When the shock is insufficient to ellect the complete tearing of the strap, its unripped mid-portion will sustain the user as shown in Fig. 9;

In order to ensure greater security, it is advisable to add to this shock absorbing device auxiliary means, such as a rope or cable o of suitable strength, said means being connected, on the one hand, to the shroud lines, and on the other hand, to the belt n of the parachutist, so that in case of complete rupture of the shock absorbing device, that is, both the strap h and the strop m, the parachutist would still be suspended by the vcable o.

Where a severe shock is to be absorbed, use can be made of two straps instead of one, and in the second strap slots can be formed as in the llrst strap, but of greater length, so as to cause the weft threads to successively come into action. With two straps, four successive stages of resistance can be provided.

When a cable o connecting the shroud lines to the belt of the parachutist is used, it is made of such a length that it comes intofaction and eilectively supports the parachutist before the sirap h, serving as the shock absorbing device, is completely torn apart. (See Fig. 11.) 'Ihe nal shock, occurring when the said strap h is completely torn apart, is then eliminated.

It is to be noted that, in the rst form of construction of the shock absorbing device provided with rupture elements, that is to say, the device 'shown in Figs. 1, 2, 3 and 4, the rupture elements offer, at every instant during the operation, an approximately constant resistance, whilst in the second form of construction, that is to say that shown in Figs. 8, 9 and 10, the rupture elements offer, at every instant during the operation, a progressive resistance in several stages. In the latter case, for an equal initial resistance, the braking action is much more rapid owing to the fact that as the resistance increases, it becomes sooner equal to the force being balanced. If a longer period of braking action was desired, the same can be effected by the use of rupture elements of increasing degrees of strength.

In order to provide a shock absorbing device of the above mentioned type which also is adapted to ensure a very rapid and very progressive braking, the following construction may be used.

A strap h of suitable length, made of silk, for example, has the warp threads in its middle portion suitably spaced apart.

This strap h is folded by winding lt several times on itself, so as to obtain (as shown in Fig. 12) loops p1, p2, p3, p4, the last of these loops, i. e. the loop p4, being double.

The strap h is slit at its middle portion in the direction of the warp threads (by cutting the weft threads) at the ends of the said loopsg This ls done in such a way that the slot formed at the vdouble loop p4 terminates at a suitable distance from the loop p3 and that the slot formed at each of the loops p3, p2, 4and-p1 constitutes, so to speak, the beginning of a slot made of unequal length on each of both sides of the said loops.

The loops p1, p2, p3. p4 are sewn together by a suitable number of rows of stitches q, made ln a suitable manner, and fastening edge stitches 1' may also be provided to flrmly hold the various loops together.y

The double loop p4 forms, owing to the slot provided therein, two loops. The belt of the parachutist is passed through one of these loops, and the ends of the shroud lines of the sail are passed through the other loop. As has previously been described, to the shock absorbing device thus constituted, there may be added an auxiliary safety cable.

What I claim as my invention and desire to secure by Letters Patent ls:-

1. A shock absorbing device for aircraft parachute having in combination a means rigid with the suspension means used for suspending the load from the sail, a means integral with the lit@ load from the sail, a means integral with the load itself, and rupture elements constituted by the weft threads of a slotted strap, these threads having a resistance which increases as their distance from the bottom of the slot increases.

3; A shock absorbing device for aircraft parachute having in combination a means rigid with the suspension means used for suspending the load from the sail, a means integral with the load itself, and rupture elements constituted by the weft threads of. a folded strap wound several times on itself so as to form loops of different size, this strap being slit at its middle portion, in the direction of the warp threads, at the ends of the said loops.

4. In combination, a parachute having shroud lines` and a shock absorbing device therefor, said device having means for attachment to the parachute and means for attachment of the same to a load, and a resilient ring embracing the shroud lines of the parachute and means for holding said ring to said shroud lines.

5. In combination, a parachute and a shock absorbing device therefor, said device comprising a strap folded upon itself and having its adjacent portions united by a multiplicity of threads constituting a series of rupturable elements, one portion being attached to the parachute and the other portion having means for attachment to a load.

6. A shock absorbing device for aircraft parachutes, comprising a folded strap, a closed ring passing through the folded end of the strap, the

other end of the strap being `slotted to divide the strap into two adjacent portions, one of said portions being connected to the parachute, the other portion having means for attachment to a load, and the weft threads of the strap constituting a multiplicity of rupturable elements.

7. A shock absorbing device for aircraft parachutes, comprising a strap having two longitudinal parts, one of said parts being connected to the parachute and the other part having means for attachment to the load, said parts being longitudinally severable by the rupture of the weft threads of the strap.

8. A shock absorbing device for aircraft parachutes, comprising a strap having two longitudinal parts, one of said parts being connected to the parachute and the other part having means for attachment to xthe load, said parts being longitudinally severable by the -rupture of the weft threads of the strap, and means for permanently uniting the two parts.

GABRIEL TRICAU. 

